Plant cultivating method, cultivating device, and its lighting device

ABSTRACT

A plant cultivating device (A), comprising aluminum long square pipe trays ( 5 ) for storing plants ( 35 ) together with culture solution, a conveyor device ( 2 ) for feeding the trays ( 5 ) in order in lateral direction, and a lighting device ( 3 ), having a number of light-emitting diodes disposed thereon, located over the conveyor device ( 5 ), the lighting device ( 3 ) being disposed so as to be higher gradually from the upstream side to the downstream side of the conveyor device ( 2 ), wherein a funnel-shaped holder ( 30 ) holding the upper part of the plant ( 35 ) is provided on the upper surface of the tray (5), and a planting conveyor ( 6 ) and a harvesting conveyor ( 7 ) for supply and retrieval, a reflecting wall ( 8 ) provided between these conveyors and the conveyor device ( 2 ), and transfer bars ( 41 ) for transferring the trays ( 5 ) between the conveyor device ( 2 ) and the planting and harvesting conveyors ( 6,7 ) are installed on the upstream and downstream sides of the conveyor device ( 2 ).

FIELD OF THE INVENTION

This invention relates generally to a plant cultivating method, acultivating device, and its lighting device, and more particularly to aso-called industrial cultivating method, a cultivating device, and itssuitable lighting device, wherein seeds or seedlings are planted intrays to which culture solution containing water and nutriments suppliedthrough a feed-water pipe, trays being carried by a conveyor device andilluminated by artificial daylight (in some cases, natural daylight).

In addition, plants described herein include vegetables, fruits, andmushrooms etc.

DESCRIPTION OF BACKGROUND ART

This kind of plant cultivating device has been invented by theapplicant. For example, in the Japanese Unexamined Patent PublicationNo. 245646/1994, a multistory work bench as a plant cultivating deviceis disclosed. The bench has a number of trays hanged by a chain conveyorcirculating in a building, wherein the cultivating process of plants isso automated that only supply and retrieval of trays to and from theconveyor is done by workers, seedlings being planted in the trays. Andin the Japanese Unexamined Patent Publication No. 136790/1998, acultivating shelf is disclosed. The shelf employs a fixed shelf frame, acultivating vessel placed on the shelf frame, and a light sourceequipped with light-emitting diodes etc. located over the each vessel.Further, in the Japanese Unexamined Patent Publication No. 106757/2000,another plant cultivating device is disclosed. The device employs aplurality of conveyors above and below, up and down mechanism for supplyand retrieval located at each input side and output side of theconveyor.

The multistory work bench type plant cultivating device has complicateddrive mechanisms and requires complex supporting methods. Since thetrays are aligned with relatively large intervals, the spaces betweentrays are useless when the plants are in their stage of being seeds orseedling. The useless spaces require longer water-supply pipes and alsocause low illumination efficiency due to longer intervals between thelight sources. In the cultivating shelf, it is possible to move thevessel to a larger shelf depending on the growth of the plants, but itinvolves great difficulties. In the Japanese Unexamined PatentPublication No. 106757/2000, a particularly large space is required inthe grown stage of the plants causing insufficient efficiency of theillumination.

It is known in the field of hothouse cultivation of vegetables to employlighting devices such as fluorescent lamps for illuminating the plantsin order to get the effects similar to prolonged daylights. Particularlyin industrial cultivation of vegetables, the cultivating vessels areplaced on the several tiered shelf and illuminated by lighting devicesto secure sufficient cultivating area.

In this case, it is disclosed to use a lighting-emitting panel on whicha number of light-emitting diodes (LED) are arranged as a lightingdevice for the illumination of plants (for reference: the JapaneseUnexamined Patent Publication No. 275779/1997 etc.). Such a lightingpanel comprises a circuit pattern formed on a aluminum board, and anumber of LED arranged on the circuit pattern, the LED being enclosed onthe pattern using a translucent synthetic resin, wherein a reflectingplate is sometimes inserted between the LED and the board in order toincrease light volume.

Conventional lighting devices such as fluorescent lamps consume a largeamount of electric power causing high electricity charges, and theirlarge amount of heat emission requires a measurable amount of powerconsumption in the air conditioners. On the other hand, the lightingpanel using LED has a problem that it has no advantage over thefluorescent lamps in the durability because of probable degradation inhigh environmental humidity. Further, it has other problems that in thecase of using large number of LED the manufacturing process takes agreat deal of labor, and that the light volume of the panel isinsufficient. The process is as follows: a LED is soldered on thecircuit pattern formed on the base, an electrode is soldered on thecircuit pattern, the LED and the electrode are bonded using a gold wire,and then a metal mold is mounted on the circuit pattern into whichmelted translucent synthetic resin such as epoxy resin is poured toenclose them within the mold. In the case that a reflecting plate isemployed, the LED is soldered on the dish reflecting plate first, andthen soldered on the circuit pattern of the base, wire bonded, andfinally enclosed with the resin.

The present invention is directed to save the useless space and toincrease the lighting efficiency of the conventional plant cultivatingdevices, and also directed to provide a lighting panel having thefeature of low electric power consumption, low heat emission, and highdurability. In addition, another object of the invention is to provide alighting panel having large light volume and easy to manufacture.

DESCRIPTION OF THE INVENTION

The first aspect of this invention is the cultivating method provided bysetting seedlings in a tray filled with culture solution; carrying thetrays by mean of a conveyor device; illuminating the seedlings bylight-emitting panel with large number of light-emitting diode set in aslant over the conveyor device so as to be gradually apart from theconveyor device along with the upstream side to downstream side of theconveyor device; and at the same time, circulating cooling water in thepiping located at the rear surface of the light-emitting panel.

The second aspect of the cultivating method is provided by soaking rootsof seedlings in a tray filled with culture solution; providing atransparent or half-transparent funnel-shaped holder on the uppersurface of the tray for holding the upper part of the plants; carryingthe trays by a conveyor device; and illuminating the plants by alighting device, which is located over the conveyor device.

The present invention of the cultivating device comprises a conveyordevice to carry plants; a lighting-emitting panel with a large number oflight-emitting diode set in a slant over the conveyor device; and apiping to circulate a cooling water is located rear surface of thelight-emitting panel; wherein the lighting device is disposed so as tobe gradually apart from the conveyor device along with the upstream sideto downstream side of the conveyor device. And it is preferable that theculture solution being in its temperature of 10 to 20° C.; and the traybeing made of aluminum or aluminum alloy.

The second aspect of the cultivating device comprises a tray to hold thestub of plants, in which the root of seedlings is soaked in filledculture solution; a conveyor device to carry the trays; a lightingdevice located over the conveyor device; and a transparent or halftransparent funnel-shaped holder on the upper surface of the tray forholding the upper part of the plant.

The third aspect of a cultivating device comprises a tray to hold thestub of plants, in which the root of seedlings is soaked in filledculture solution; a conveyor device to carry the trays; a lightingdevice located over the conveyor device; an up and down conveyor forsupply and retrieval respectively located apart from the each end of theconveyor device; a partitioning provided between these conveyors and theconveyor device; and a transfer bar for transferring trays between theconveyor device and the up and down conveyors, the said bar beingmovable in both ways along the extension line of the conveyor device;wherein the partitioning has a opening for enabling the transfer bar togo in and out along the extension line of the conveyor device.

In this cultivating device, it is preferable to provide a door so as tobe capable of to close and to open the opening located on thepartitioning.

And also, it is preferable to provide a reflecting surface to reflectthe light from the lighting device inside of the partitioning and thedoor.

Further, it is preferable in this invention to provide an up and downconveyor with an up and down arm to hold the tray, the arm beingequipped with a horizontal portion extended toward the conveyor deviceand also equipped with a finger extended downward from the front end ofthe horizontal portion and further extending in the direction oppositeto the conveyor device.

The forth aspect of a cultivating device comprises a tray to hold thestub of plants, in which the root of seedlings is soaked in filledculture solution; a conveyor device to carry the trays; a lightingdevice located over the conveyor device; an up and down conveyor forsupply and retrieval respectively located apart from the each end of theconveyor device; a wall to surround the conveyor device; a transfer barfor transferring trays between the conveyor device and the up and downconveyors, the said bar being movable in both ways along the extensionline of the conveyor device; wherein the partitioning has a opening forenabling the transfer bar to go in and out along the extension line ofthe conveyor device.

According to the present invention, the plants being carried by theconveyor grows under the illumination by a light-emitting panel, andbecome higher as they move to the down stream side of the conveyor. Inthe first aspect of the cultivating method, since the light-emittingpanel is disposed in a slant so as to be gradually apart from theconveyor device along with the upstream side to downstream side of theconveyor, the distance between the light-emitting panel and the upperend of the seedlings is kept about the same, thereby enabling nearbyillumination of the plants to get higher illumination efficiency.Luminous efficiency of light-emitting diodes is degraded by temperaturerise due to the light-emission. This method cools the light-emittingpanel due to the light-emission of the light-emitting diodes.

The first aspect of the plant cultivating device is preferable to theabove cultivating method. And by maintaining the temperature of theculture solution around 10 to 20 degrees Celsius, it prevents plantsfrom hazards of excess growth etc. Further, because the tray is made ofaluminum or aluminum alloy, it can cool the surrounding air, therebyavoid the temperature rise due to the light emission of thelight-emitting diodes and maintain the surrounding in preferabletemperature.

In the second cultivating method, the upper part of the stub of plantsis held by a transparent or half transparent funnel-shaped holderlocated at the upper surface of the tray, thereby the green vegetablessuch as lettuces being bundled upward. Therefore, even in the smallerintervals between the adjacent plants, the leaves do not intertwine, andthe upward-directed leaves are illuminated sufficiently by the lightingdevices, whereby the many stubs of plants can be accommodated in a traywith efficient illumination by the lighting devices.

Because the leaves of plants are bundled upward with the funnel-shapedholder, the height of plants becomes higher. For that reason, it ispreferable for the second cultivating method to be combined with thefirst cultivating method so as to illuminate the plants from a higherposition.

The second aspect of a cultivating device can carry out the secondcultivating method efficiently.

In the third aspect of a cultivating device, a partitioning is providedbetween the conveyor device and the up and down conveyor, whereby thepartitioning prevents the light of the lighting device from spreadingoutside and make easy to control the temperature inside. Handling oftrays between the conveyor device and the up and down conveyor is easilydone through the opening provided on the partitioning. In the case thata door is provided so as to be capable of closing and opening theopening, the door closes the opening all times except when the trays aretransferred through the window, shutting off the light of the lightingdevice at the window and enabling easier control of the temperature. Inthe case that a reflecting surface to reflect the light of the lightingdevice is provided inside of the partitioning and the door, theefficiency of the lighting is further increased.

Further, the transferring between the up and down conveyor and thetransfer bar can be done through the opening preventing the interferencebetween the door and the finger. Further, the opening and closingmovement of the door is connected with the forward and backward movementof the transferring bar so as to simplify the drive and controlmechanism.

In the fourth aspect of the cultivating device, the wall is placedsurrounding the conveyor device, and wall reflects the light of thelighting device, so it prevents from spreading of the light fromlighting device.

A lighting-emitting panel of this invention comprises a base plate, acircuit board mounted on the base plate, a light-emitting unit providedwith a number of lamps arranged and fixed on the circuit pattern of thecircuit board, a translucent cover placed with a space adjacent to thebase plate, a sealing material sandwiched between the base plate and thecover to keep the space airtight, and the lamps being fixed on thecircuit board using a conductive adhesive.

In these light-emitting panel, it is preferable that a frame issandwiched between the base and the cover, wherein a sealing material ispacked around the frame, the space is filled with inactive dry gas, anda desiccant and/or deoxidizer is accommodated inside of the frame.

Further, it is preferable that the lamp is provided with a concavereflecting plate, a light-emitting element mounted on the reflectingplate, a bonding wire to bond the light-emitting element and anelectrode, and a translucent molding material of synthetic resin toenclose the above described part, and that the conductive adhesive iscomposed of soldering cream a kind of heat setting adhesive.

The light-emitting unit of this invention comprises a circuit boardhaving a circuit pattern, a number of lamps arranged and fixed with aconductive adhesive, wherein the lamps are enclosed in a packagetogether with a reflecting plate, a light-emitting element, a bondingwire, and an electrode using a translucent molding material.

In this light-emitting unit, it is preferable that the circuit board ismade of aluminum, forms an insulation layer on the circuit board ofaluminum, wherein a circuit pattern is formed on the insulation board.And further it is preferable that a layer of soldering cream is formedon the circuit pattern, wherein the layer is heated after mounting ofthe lamps so as to be melted and then be cooled down naturally forsolidifying, thereby fixing the lamps on the circuit pattern. Inaddition, the base can be served as a circuit board.

The light-emitting panel of this invention employs light-emittingelements as a light source, it consumes relatively small amount ofelectric power compared with conventional light sources as fluorescentlamps, and it has small amount of heat emission which reduces the powerrequired for the air conditioning. Further, the selection of alight-emitting element having a specific wavelength allows compositionof a light-emitting panel well suited for any object.

The light-emitting panel provided with light-emitting elements isaccommodated in a space between the base and the translucent cover.Since the space is made airtight with a sealing material, it shuts offthe humidity incoming from the outside and decreases degradation of thelight-emitting elements due to the humidity achieving high durability.

Because the space is hermetically sealed, heat coming up with thelight-emission is inclined to be accumulated in the space. However, theheat is radiated outside through the base plate keeping the heataccumulation relatively low. Furthermore, since the lamps manufacturedseparately are mounted and fixed to the circuit board with adhesive, inthe case of using many lamps, it is easy to control the quality of thewhole manufacturing process and each lamp.

The light-emitting panel with its frame sandwiched between the base andthe cover, a sealing material being packed around the frame, the spacebeing filled with dry gas, and a desiccant and/or a deoxidizer beingaccommodated in the frame, has accurate spacing between the base plateand the cover and has large unit strength. Further, because the sealingmaterial is needed only to seal the gap between the frame, the baseplate, and the cover, it has large efficacy in sealing. Furthermore, bythe effect of the desiccant and the deoxidizer, the amount of humidityand/or oxygen contained in the space is very low, thereby thelight-emitting elements such as light-emitting diodes being protectedagainst the degradation due to humidity and/or oxygen.

In the case that the lamp is provided with a concave reflecting plate, alight-emitting element mounted on the reflecting plate, a bonding wireto bond the light-emitting element and an electrode, and a translucentmolding material of synthetic resin to enclose the above described part,a relatively large amount of light is obtained by the reflection oflight from the light-emitting element. Further, since the light-emittingelement, an electrode, and a bonding wire are enclosed in a packageusing a molding material, a number of lamps are easily handled in anautomatic mounting process of the light-emitting panel manufacturing,thereby the panels being manufactured efficiently.

In the case that, as the conductive adhesive, soldering cream a kind ofheat setting adhesive is used, a large number of lamps can be fixed onthe circuit board at a time only by a heating process after mounting ofthe lamps on the circuit board.

In the light-emitting unit of this invention, the employment of the lampin which a reflecting plate, a light-emitting element, a bonding wire,and an electrode are enclosed using a translucent molding material;allows easy handling of a number of the lamps. In the case that theinsulation layer is formed on the circuit board of aluminum and acircuit pattern is formed on the insulation layer, the circuit boardweighs light enabling easy manufacturing. Moreover, in the case that thebase plate can be served as a circuit board, number of necessary partsbecomes fewer enabling the further easy manufacturing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rough cross sectional view of the cultivating device of thisinvention;

FIG. 2 is a side view of a cultivating device of this invention showingthe device wholly;

FIG. 3 is a plan view of the cultivating device;

FIG. 4A is a perspective view with a fragmentary sectional view showingan embodiment of a tray of the cultivating device, and FIG. 4B is across sectional view of the main part of the tray;

FIG. 5 is a perspective view of an embodiment of a transfer mechanism ofthe cultivating device of this invention;

FIGS. 6 and 7 are process drawings of the transfer mechanism;

FIG. 8 is a rough cross sectional view showing an embodiment of thetransfer mechanism in harvesting conveyor side;

FIG. 9A is a perspective view showing an embodiment of a lighting deviceof this invention;

FIG. 9B is a cross sectional view of the main part of the lightingdevice;

FIG. 10 is a perspective view with a fragmentary sectional view showingthe other embodiment of a light-emitting panel wholly;

FIG. 11A is a cross sectional view of the main part of thelight-emitting panel showing its other embodiment; and FIG. 11B is amain part of a light-emitting unit used in the above light-emittingpanel;

FIG. 12A is a cross sectional view of the light-emitting unit showing amanufacturing method of the unit; and FIG. 12B is a plan view of themain part of FIG. 12A.

FIGS. 13A, 13B, 13C and 13D are rough process drawings showing themanufacturing method of the light-emitting panel of this invention;

FIGS. 14A, 14B and 14C are rough process drawings of the showing theother embodiment of the manufacturing method of the light-emitting panelof this invention;

FIG. 15 is a cross sectional view showing the other embodiment of thelamps related to this invention;

FIGS. 16A, 16B, 16C, 16D and 16E are cross sectional views showing anembodiment of the light-emitting element of the lighting device;

FIG. 17 is a schematic diagram showing an embodiment of a controlcircuit of the light-emitting panel;

-   -   FIGS. 18A, 18B and 18C are schematic diagrams showing the other        embodiment of the control circuit of the each light-emitting        panel;

FIG. 19 is a perspective view showing an embodiment of an indicatingpanel using the light-emitting panel of this invention;

FIG. 20 is a perspective view showing an embodiment of a cultivatingshelf using the light-emitting panel of this invention;

FIG. 21 is a cross sectional view showing the other embodiment of thelight-emitting panel of this invention; and

FIG. 22 is a cross sectional view showing the other embodiment of thelight-emitting panel of this invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

The plant cultivating device is wholly described herein referring toFIG. 2 and FIG. 3. A plant cultivating device A shown in FIG. 2 and FIG.3 comprises multistage conveyor device 2, 2 . . . assembled in abuilding 1, a lighting device 3 fit under each conveyor device 2, a fixplanting conveyor 6 to supply a tray 5, a harvesting conveyor 7 toretrieve the tray to conveyor device 2. The fix planting conveyor 6 andthe harvesting conveyor 7 move up and down respectively. Further, theplant cultivating device comprises pipes for cooling water to cool thelighting device 3, a water supply facility to supply solution to thetray 5 on the conveyor device 2 for hydroponics, and incidentalfacilities such as drainage facility to drain water from the tray 5. Inthis embodiment, each stage of the conveyor device 2 has practically thesame composition, wherein the same or different plants can be cultivatedin the each stage.

The size of the building 1 is, for example, 10 m high, 12 m long, and 10m width with heat-insulated wall of 10 cm thickness, wherein the size ischangeable according to the kind of plants to be cultivated.

Further, in this embodiment, reflecting walls 8 (partitioning) toreflect lights from the lighting device 3 are provided between the fixplanting conveyor 6 and the conveyor device 2, and between the conveyordevice 2 and the harvesting conveyor 7. The reflecting wall 8 can beprovided so as to surround the conveyor device 2. A heat insulationmaterial can be used as the reflecting wall 8. For example, white foampolystyrene has both effects. Light-reflective metal films such asaluminum films can be attached to inside of the reflecting wall 8 inorder to reflect lights.

In the lower part of the building 1, a work room 10 is provided forworkers 9 to put the tray 5 on the fix planting conveyor 6 and toretrieve the tray from the harvesting conveyor 7. Over the work room,the conveyor device 2 of, for example, about 10 stages is provided. Thecentral part of the work room 10 is a seeding area 10 a, the near partof the fix planting conveyor 6 is a breeding area 10 b, and the nearpart of the harvesting conveyor 7 is a harvesting area 10 c to harvestplants by unloading the trays 5 from the conveyor device 2.

As shown in FIG. 3, the every stage of the conveyor device 2 is locatedat right and left side of the building 1, wherein the conveyor device 2supports the tray 5 at somewhat inside from the right and left end ofthe tray 5 which is long in the crosswise direction.

Moreover, a plurality of the rail 11 is provided between the near partof the right and left end of the conveyor device 2, and between theconveyor device 2 to slidably support the tray 5.

As shown in FIG. 1 and FIG. 2, the lighting device 3 having a planesurface is supported by a stay 12 under the bottom of the conveyordevice 2 with some space in between, wherein the lighting device 3 isdisposed so as to be lower in the upstream side and higher in the downstream side illuminating the tray 5 of one stage under.

The reason for the lighting device 3 is inclined is that, in early stageof the plant growth, it is necessary to bring the lighting device 3 nearto the plants in order to illuminate the plants because of therelatively lower height of the plants.

Under the bottom of the lowest stage conveyor device 2, the lightingdevice 3 is omitted, but a lighting device 3 to illuminate the tray 5 onthe highest conveyor device 2 is provided near the ceiling of thebuilding.

As the lighting device 3 a fluorescent lamp or an electric lamp isusable, but a light-emitting diode (LED) which emits a light whose wavelength is optimum for the plant cultivation is preferable.

In the case that a number of light-emitting diode is used in a panellike arrangement, as the lighting device 3, selection of different colordiodes depending on the kind of plants is possible. For example, twothird of each light-emitting panel is occupied by red colorlight-emitting diodes, one third is by blue color light-emitting diodes.The total luminous intensity of the light-emitting panel is preferableto be from 2000 to 3000 lux. However, it can be set at preferredintensity depending on the plants to be illuminated, and also theintensity can be arbitrarily time controlled.

The Reference Numeral 13 in FIG. 2 shows a fan to circulate air in thebuilding 1 which is provided with an air conditioner for temperature,humidity, and CO₂ control. In the case that the environment of the plantgrowth is preferred to be changed in the midway of the conveyor device2, a translucent synthetic resin sheet can be used as a partition.

In addition, it is preferable to automatically control the variousenvironmental factors by continuous monitoring of the gas density,temperature, and humidity with each sensor.

The conveyor device 2 is described herein referring to FIG. 1 and FIG.3.

The conveyor device 2 located at right and left side can be composed ofone belt conveyor each. The belt conveyor comprises a rotary drive drum14 located at the end, a large number of an idler 15 between the drum14, a belt 16 circulating around them, and a motor (Reference Numeral Min FIG. 5) to drive the drum 14. The drive drum 14 of the right and leftconveyor device 2 is coupled each other by a drive axis (ReferenceNumeral 17 in FIG. 5). Such a circulating conveyor device as a chainconveyor can be used in lieu of the belt conveyor. The conveyor devicecan be composed of a chain of a plurality of small independent conveyorsfrom the fix planting conveyor 6 to the harvesting conveyor 7, whereinthe carrying speed of the every conveyor can be varied each other.

As shown in FIG. 2, the fix planting conveyor 6 is constructed so thatfour sprockets 20 located at the upper and lower end hold the endlesschain 21, which is like a chain conveyor set in a vertical direction.The chain 21 is provided with a receptacle 22 to hold the tray 5 at aninterval fitted to that of the conveyor device 2. In addition, as shownin FIG. 1, the receptacle 22 has, in relation to the transfer mechanismdescribed later, horizontal portion 23 extending forward and L-shapefinger 24 which extends downward from the front edge of portion 23 andfurther extends backward from the lower end. On the edge of the finger24, a hook 25 is provided.

The chain 21 is driven circularly by a motor (not shown in the figure.)so that the front side goes up with the back side going down. Since theharvesting conveyor 7 is substantially the same as the fix plantingconveyor 6, descriptions are abbreviated by assigning the same referencenumerals to the same portions.

FIG. 4A shows a preferable embodiment of the tray 5. The tray 5 is madeof aluminum or aluminum alloy with its both ends closed by a cover 5 aetc. The upper surface is provided with openings for cultivating plantsat an interval of 50˜300 mm. Like showed in FIG. 4B, the tray 5 has aliquid filled structure contains culture solution 27. On the one end ofthe upper surface of the tray 5, there is a opening 5 b for supplyingculture solution, and on the bottom of the another end, there is a drainpipe 5 c passing through the bottom for draining culture solution. Theheight of the drain pipe defines the upper limit of the solution level,thereby culture solution exceeding the level being drained through thedrain pipe 5 c. The temperature of the culture solution is maintained intemperature around 10˜20° C. usually, or more preferably in temperaturearound 15˜16° C. Since the tray 5 is made of aluminum or aluminum alloy,it can cool the surrounding air, thereby preventing plants from hazardsof excess growth etc. by withholding temperature rise caused by the roomtemperature of 22˜23° C. or the lighting devices 3 in not only the rootof but also stems and leaves of plants.

In this embodiment, the opening 26 of the tray 5 is circular in which afunnel-shaped holder 30 is mounted. On the upper inside of the centralpart of the tray 5, there is a rib 5 d projecting downward, and theopening 26 is located zigzag avoiding the rib 5 d. The holder 30 iscomposed of a cylindrical base 31 set in the opening 26 and of theconical holding part 33 extending upward from the base 31.

The upper edge of the holding part 33 has a fold 32 to reinforce theholding part 33. The holding part 33 has no preference of cylinder typeor square type. The tray 5 can be wholly molded integrally usingsynthetic resin etc. For example, it can be manufactured as follows; asynthetic resin sheet is molded into the holing part 33 and the bottomedbase 31 by hot pressing; the outskirt of the fold 32 is finished bytrimming; and the bottom of the base 31 is punched out. It is preferablefor the holding part 33 to be transparent or half transparent so as tolet through lights. When the holder 30 is set in the opening 26 as shownin FIG. 4B, the base 31 touches the inside wall of the tray 5 or the rib5 d preventing the holder 30 from falling down. However, it is allowableto provide a collar on the boundary of the base 31 and the holding part33.

The use of such holder 30 enables to hold the leaves of plants 35 suchas green vegetables called “sunny lettuces” without spreading.

When the plants 35 are planted directly in the opening 26, the leaves ofthe plants 35 spread in the lateral direction with their growth as shownby the imaginary line. When the leaves spread wide as shown in thefigure, they interfere each other with the leaves of the adjacent plant35 and sometimes ripped in harvesting. Furthermore they become poorlyilluminated due to shadowing by the leaves of adjacent plants, therebynecessitating larger interval of the opening 26.

However, as shown in FIG. 4A and FIG. 4B the tray 5 has the holding partwhich bundles the leaves of plants upward, thereby preventing the leavesfrom spreading as shown by the imaginary line and avoiding interferenceof the adjacent leaves each other. Resultantly, the interval of theopenings can be reduced to about 50˜200 mm, which increases gather perunit area. Furthermore, the plants can be fully illuminated by thelighting devices.

The fix planting conveyor 6 is located so as to avoid interference withthe carrying conveyor device 2. For this reason, as shown in FIG. 5, atransferring mechanism 40 for transferring the tray 5 between these twoconveyors are provided. The transferring mechanism 40 is a combinationof transfer bar 41 moving back and forth and the fix planting conveyor 6moving up and down. The transfer bar 41 is, for example, a flat board ora pipe with an upward hook 42 on its front edge for holding the tray 5stably. The transfer bar 41 is supported by a guide 43 so as to bemovable back and forth, and is driven back and forth by a underneathrack 44 and a pinion 45 driven by a motor M2.

Multiple, for example two to three, transfer bar 41 are provided inparallel for enabling stable transfer of the tray 5 which is long fromside to side. The pinions 45 driving the transfer bar 41 are driven byeach motor M2 synchronously, thereby being capable of synchronousoperation. In addition, other types of direct drive actuators such asair cylinders or hydraulic cylinders can be used as the driving device,but the motor drives are preferable.

As described previously, the reflecting wall 8 is provided between thefix planting conveyor 6 and the carrying conveyor device 2. Thereflecting wall 8 has a opening 50 or a window for enabling the transferbar 41 to go through. In this embodiment, a door 51 is provided on thefront edge of the transfer bar 41 to close the opening 50. The door 51can be composed of white foam polystyrene which is the same as thereflecting wall, or can be composed of aluminum foil attached on theinner surface.

Since the location of the receptacle 22 of the fix planting conveyor 6and the transfer bar 41 can be staggered from side to side, originallythe tray 5 can be transferred to the transfer bar 41 when the transferbar 41 goes ahead and the fix planting conveyor 6 goes down. However, inthis embodiment, because the door 51 is provided on the front edge ofthe transfer bar 41, it is necessary to avoid interference between thedoor 51 and the receptacle 22. As described previously, it is for thisreason that the receptacle 22 is provided with the finger 24 which takesout the tray 5 backward. Followings are the description of thetransferring procedures from the receptacle 22 to the transfer bar 41referring to FIG. 1, FIG. 6 and FIG. 7. The motor of the fix plantingconveyor 6 and the motor M2 of the transfer bar 41 are controlled sothat the following procedures are carried out in the sequence.

At the start, as shown in FIG. 1, the receptacle 22 is standing at theposition where it does not interfere with the door 51 and upper than theopening 50 of the reflecting wall 8. In this condition, as shown in theupper part of FIG. 6, the transfer bar 41 is moved toward the fixplanting conveyor 6 and the hook 42 is positioned at the back of thetray 5(Step 1). Then the fix planting conveyor 6 is driven to lower thereceptacle 22 and the tray 5 is put down lightly on the transfer bar 41(Step 2). Subsequently, the transfer bar 41 is moved backward to be ableto hold the tray 5 with the hook 42 (Step 3).

Continuously, as shown in the upper part of FIG. 7, the receptacle 22 isslightly lowered and the transfer bar is again moved forward (step 4).Next, in this condition the receptacle 22 is elevated to the positionwhere it does not interfere with the door 51 (Step 5). Further, thetransfer bar 41 is moved backward to transfer the tray 5 to the conveyor5. After that, the transfer bar is moved backward to close the opening50 of the reflecting wall 8 with the door 51.

Operation of the receptacle 22 and the transfer bar 41 in the sequencedescribed above prevents the interference between the door 51, the tray5 and the receptacle 22.

The provision of the door 51 allows automatic close of the opening 50without provision of other drive sources, and also allows to securereflection and thermal insulation of the reflecting wall 8.

Other driving source such as motors or air cylinders can be used withupper part of the door 51 being hinge-jointed to the reflecting wall 8.In this case, the receptacle 22 can be provided only with an upwardprojection for hooking the tray 5 on the front edge of the horizontalportion 23. And, after the tray 5 is transferred to the transfer bar 41by lowering the receptacle 22, it is not necessary for the receptacle 22to be elevated, and only necessary to make an escape downward.

The tray 5 can be transferred to the conveyor all together from thereceptacle 42 of each stage of the fix planting conveyor 6, or can betransferred with respect to each stage of the fix planting conveyor 6.The emptied fix planting conveyor 6 is loaded with the next planted tray5 by a worker 9 as shown in FIG. 2.

As the fix planting conveyor 6 and the transfer mechanism 40, notlimited to the above devices, various devices such as those used inmulti story warehouses can be employed. For example, the transfer bar 41described above can be such a device which goes up and down by itself tothe chain. In this case, the slight lowering of the front side of thefix planting conveyor becomes unnecessary, and the transfer from thetransfer bar 44 to the carrying conveyor 2 becomes smooth.

As the harvesting conveyor 7 shown in FIG. 8, substantially the samedevice with the fix planting conveyor 6 can be employed, in which onlythe circulation and the sequence of operation is reversed.

However, when the tray 5 is taken out from the conveyor device 2,tangling of leaves of plants to those of the next tray sometimes occurs.It is preferable to provide a shoulder near the front edge of thetransfer bar 41 for hooking the tray 5 so as to prevent the tangling.

The tray 5 retrieved from the harvesting conveyor 7 is brought down to aworking area 10 c by the worker and the plants only are harvested.

The emptied tray 5 is used again in a planting area 10 a so as to beplanted seeds. The tray 5 is generally filled with water, nutriment,substance retentive of water, and seeds only; in other words,cultivation by hydroponics. Soil can be put in the tray and seeds areplanted in the soil. Seedlings can be planted in the tray from thefirst.

Next, a preferable embodiment of the lighting device 3 employinglight-emitting diodes is described. Luminous efficiency of lightemitting-diodes is degraded by temperature rise due to thelight-emission. In addition, in the building 1, the indoor air ismaintained at high temperature and humidity, causing further degradationof the luminous efficiency.

In this embodiment, as shown in FIG. 9A, the base plate of the lightingpanel P, on which a number of light-emitting diode is mounted, is madefrom a metal plate such as aluminum having high thermal conductivity.The rear side of the light-emitting panel P is provided with a piping 56to pass through cooling water. As for the metal plate, other plates suchas ceramics having high heat conductivity can be used.

In the light-emitting panel P of FIG. 9B, the piping 56 is made fromrectangular pipes, wherein a stud bolt 57 is projected from the rear ofthe light-emitting panel P; and a folded metal mounting plate 58 andnuts 59 fix the piping 56. The use of such rectangular pipes ispreferable because it enhances heat conduction.

Furthermore, the light-emitting panel P comprises a base plate 60 ofaluminum etc., a frame 61 made from aluminum rectangular pipe etc.located at the bottom of the panel, a cover 62 laid on the undersurfaceof the frame 61, a sealing material 63 such as silicone resin packedaround the periphery of the frame 61.

On the undersurface of the base plate 60, a circuit board 65 on which anumber of lamps 64 having a light-emitting element such as alight-emitting diode is arranged. Inside of the frame 61, a desiccant 66is accommodated. The space N between the base plate 60 and the cover 62is filled with inactive gas such as nitrogen gas reducing thedegradation due to oxidation of the light-emitting diode. Dry air can beused in place of the gas. The space N can be vacuumized to the degree of0˜0.3 atm. In this case, not only the degradation due to oxygen orhumidity is reduced, but also the heat conduction due to convection fromthe cover 62 side is reduced. A sealing material such as butyl putty 67is sandwiched between the frame 61 and base plate 60, the frame 61 andthe cover 62 for maintaining the air-tightness of the space N togetherwith the silicone resin sealing material 63.

As shown in FIG. 1 etc., the lighting-emitting panel P is set at aslant. Cooling water is circulated in the piping 56 located at the rearsurface of the light-emitting panel P, and the piping 56 being also setat a slant for enhancing the circulation of the water.

In addition, the light-emitting panel P can be set in step-wise with itspiping also being set in step-wise on the rear surface. As well, dry airin its temperature of about −40° C.˜−80° C. can be fed in the piping 56for cooling the lighting device 3 directly or indirectly through coolingplates. Hot air after cooling the lighting device 3 can be recovered byducts directly or discharged into the room.

Further, a light source such as light-emitting diode can be enclosed insuch as a heat-insulated box and cooled by cold dry air or cold water,wherein the light is guided by optic fivers from the light source to theundersurface of the conveyor device 2 (upper side of the tray). In thiscase, the light source can be cooled sufficiently and condensation canalso be prevented resulting in protection of the light source.Furthermore, exterior natural light can be guided by optic fibers to theundersurface of the conveyor device 2 in the building.

As shown in FIG. 10, the light-emitting panel P is basically the panelon which the above described board 65 and the light-emitting unit 69composed of the lamp 64 are set in array; a plurality of the board anddozens or several hundred of the unit throughout the length and breadthof the panel respectively. The board 65 of the light-emitting unit 69can be about the same in size as the base plate 60. Further, the baseplate 60 can be served as the board 65 (refer to FIG. 22). Suchlight-emitting panel P is also used as a message board for spreadingprescribed message by connecting the terminal of the circuit pattern toa computer controlled circuit and making light emission of manylight-emitting diodes in sequence.

The use of light-emitting diodes whose color is red, green, violet etc.allows color screen image display. Since such light-emitting panels havelarge light volume, large message impress can be expected. Additionally,simplicity of the manufacturing process allows low cost manufacturing inthe case that it is used in a large scale light-emitting panel of thesize from scores of centimeter to about 5 m.

The kind of the light-emitting element used in this invention is notlimited particularly, and generally light-emitting diodes are used. Itis preferable to use red light of wave length 600 nm which has thehighest efficiency in photosynthetic reaction in plants. The circuitpattern 70 can be formed by a wiring pattern connecting eachlight-emitting diode in series or in parallel or by a matrix wiringpattern. Discrete wiring by connecting each wire can also be doneotherwise.

The wiring between the each board 65 is sealed off using a sealantdescribed later after completion of the each wiring and drawing out ofthe wire from the corner of the light-emitting unit 69.

The light-emitting panel P shown in FIG. 11A comprises the base plate 60composed of a metal plate having high heat conductivity such as aluminumand the cover 62 made of glass located with a space H facing the baseplate 60. The base plate 60 and the cover 62 are rectangularrespectively with the sandwiched frame 61 in between. The frame 61 is arectangular pipe made by folding, for example thin metal plate, into ashape like C or into a square in cross section, inside of which there isa mating face 68 among the edges. In the frame 61, a desiccant is filledin. A deoxidizer can be filled in together with the desiccant. The frame61 can be made of synthetic resin.

In the space N between the base plate 60 and the cover 62 as shown inFIG. 11A, dry gas such as dry air is filled in. Around the frame 61, thesealing material 63 such as silicone sealant is applied to seal off thespace N between the base plate 60 and the cover 62.

A method to fill in dry air in the space N is only to assemble the baseplate 60, the frame 61 in which a desiccant is accommodated, and thecover 62 in a dry room. Even if the assembling is done in ambient air,the air becomes dry air by the influence of the desiccant 66 through themating face 68. In the case that inert gas such as nitrogen gas is used,one of the method to fill in the gas can be as following; let the airout of the space on the one side, and the gas is filled in on the otherside. In order to assemble the panel, the frame 61 and the base plate 60or the cover 62 are tacked temporarily using double-stick tapes etc.,and they can be integrated by applying sealing material 63.

The size of the base plate 60 and the cover 62 is not limitedparticularly, and various sizes of them ranging from 10 cm to about 5 ma side can be used. However, the sizes from 50 cm to 1 m a side, andparticularly 1 m a side are preferable from the aspect of easiness inassembling, transportation, and high efficiency. Further, those ofrectangular-shaped or stripe-shaped can also be used. It is preferablefor the base plate 60 to be of the thickness ranging from 0.3 to 3 mmand for the cover 62 to be of the thickness ranging from 1 to 5 mm. Thespace H between the base plate 60 and the cover 62 are preferable to bein the range of 3 to 20 mm and particularly in the range of 5 to 10 mm,though it is different depending upon the panel size.

On the base plate 60 of the light-emitting panel P shown in FIG. 11A,heat radiation fins 104 can be mounted as shown in the imaginary line.

The fin 104 can be manufactured from a thin metal plate having highthermal conductivity such as aluminum and folded into C-shape. The fin104 is preferable to be blown by an air blower.

Inside of the base plate 60, the light-emitting unit 69 are set inarray, wherein a number of the lamps 64 is arranged on the surface ofthe board 65 made of thin aluminum plate etc. and the board 65 istightly connected to the base plate 60 by brazing etc. so as to assurehigh thermal conductivity.

As shown in FIG. 11B and FIG. 12, the light emitting unit 69 ismanufactured as follows; an insulation layer 65 a made of inorganicmaterial or organic material is laid on the board 65, on which a circuitpattern 70 is formed, and the lamp 64 is mounted in place after applyingsoldering cream 71 (soldering paste). Other metal plates can be used inlieu of the board 65 made of aluminum. Although, the insulation layer 65a is laid on all over the board 65, it can be laid only on the circuitpattern 70. The circuit pattern 70 is formed by plating the whole areawith copper and removing unnecessary parts through an etching process.The soldering cream 71 is coated efficiently by making and printing theproof. Further, the board 65 can be made of insulating material, inwhich case the insulating layer 65 a is not necessary.

The lamp 64 comprises a reflecting plate 73 made from thin copper metalshaped into dish by press work with its concave side 72 aluminized, aLED (Light-Emitting Diode) 74 mounted on the concave side 72 of thereflecting plate 73, an electrode 75 located on the same surface as thatof the reflecting plate 73, a bonding wire 76 for bonding the LED 74 andthe electrode 75, and a molding material 77 of epoxy resin etc. forenclosing the above described parts. In the reflecting plate 73, thereis a residual circular projection 78 which spring up in the process ofprogressive casting in the press work.

The lower edge of the circular projection 78 can be used as the bottomfor mounting the lamp 64 by leaving the edge as flat plane. Moreover,through the bottom part, the electrode 75 and the reflecting plate 73 ofthe other light-emitting unit can be left undivided and being cut offafter enclosing with the molding material 77.

The molding material 77 is formed using translucent synthetic resin,especially thermosetting resin such as epoxy resin.

The molding material 77 has a spherical surface on its upper surface 77a facing the light-emitting diode (LED) 74, thereby increasing the lightvolume due to the lens action of the molding material 77. Furthermore,aluminizing of the concave side 72 of the reflecting plate 73 allowsconcentrated reflection of the light from the LED 74 increasing thelight volume to the front direction.

The reflecting plate 73 and the electrode 75 can be made by integralforming using an insulating material such as a sheet of synthetic resin.In this case, a piece of copper plate etc. penetrating the upper andlower surface is inserted in each part before the molding process. Aswell, following processes of making electrical pass can be employed; apass-through slot being made in each part and a electrically conductivematerial being filled in the slot, gold plated, or a combination ofthese processes.

The soldering cream 71 is a creamy micronized solder dissolved in asolvent and is publicly known. When heated, the solvent disappears intothe air and the solder is melt down by heat, filling the space betweenthe reflecting plate 73, electrode 75, and the circuit pattern 70 andhardened with fall of temperature. On these occasions, the lamp 64 isfixed on the board 65 firmly. As an electrically conductive adhesive, amaterial other than the soldering cream can be used.

FIG. 13A˜D shows other methods to manufacture the light-emitting panelP. At first, a backing material 80 of metal long plate having highelectrical conductivity such as a copper plate is pressed to form arraysof the area 81 where the lamp 64 is placed. In the press work, feedholes 82 such as perforation in photographic films are formed at thebeginning, thereby enabling high feeding accuracy. Next, the transverseslit 83 at given interval is formed to allow easy press work between theslit 83.

Further, as shown in FIG. 13B, the circular projection 78 whose insidesurface is the concaved (mark 72) is formed. The reference numeral 75 ais a part which becomes the electrode described above. The referencenumeral 84 a is an area removed later by the etching process and thereference numeral 84 b is an area left intact. After the press work andmasking, the concave side 72 is plated with white metal such as aluminumto form mirror surface for reflecting lights.

Then, as shown in FIG. 13C, the light-emitting diode 74 is fitted on thebottom of the concave side 72, and the electrode 75 is fitted on thearea 75 a. Further, the light-emitting diode 74 and the electrode 75 arebonded with the bonding wire 76, wherein the reflecting plate 73 is madeto be electrically conductive so as to be the electrode of thelight-emitting diode 74. Then, the molding material 77 is built in. Themasking is done on the rear surface and the area 84 a of copper isremoved, thereby cutting off the light-emitting diode 74 side and theelectrode 75 side and also cutting off the area 81 composing each lampunit to get the lamp 64. The long sheet can be cut off in a linepreviously at suitable process. After the each lamp 64 is made, as shownin FIG. 13D, it is mounted at a proper position on the base plate 60which also serves as a circuit board by a mounter, wherein thereflecting plate 73 and the electrode 75 are jointed directly by themethod using soldering cream described above. In the case that the baseplate 60 made from an aluminum plate etc. is used, an insulation layerand a circuit pattern are previously formed.

High precision working is required for the process of mounting thelight-emitting diode and the electrode 75 and for the process of wiringwith the bonding wire. However, since the area 81 for mounting the lampcan be positioned with relatively high precision, the work can beautomated. Further, when the reflecting plate 73 and the electrode 75are jointed to the base plate 60 after once each lamp 64 ismanufactured, it does not require such a high precision work. So it canbe mounted directly on the base plate 60 of the size about 1 m square.Therefore, any circuit board is not necessary to be provided separatelyenabling efficient manufacturing (Refer to FIG. 2).

In the lamp 64 shown in FIG. 15, the reflecting plate 73 on which thelight-emitting diode 74 is mounted and the circuit is insulated eachother, and the two electrode 75 a and 75 b are exposed on theundersurface of the lamp 64, wherein the light-emitting diode 74 and theeach electrode 75 a and 75 b is wired with the bonding wire 76 a and 76b. These compositions are used for blue light-emitting diodes 74. Othercompositions are same as described above.

FIGS. 16 a˜f show an embodiment of light-emitting element using alight-emitting diode mounted on the undersurface of the light-emittingpanel P. As shown in FIG. 16 a, the lamp 64 comprises the light-emittingdiode 74 fixed on the circuit board 65 made of aluminum etc., and themolding material 77 made of translucent, thermo-stable synthetic resinsuch as epoxy resin heaped up on the diode like semi-sphere or likeconvex lens 79. Further, in this embodiment, doubled layers of thesecond convex lens layer 79 and the third convex lens layer 79 areprovided, wherein the reference numeral 75 shows a electrode, 76 shows abonding wire, and 85 shows a kind of ring like a tundish 85 forpreventing the molding material 77 to flow out.

The heaping up of the molding material 77 of the lamp 64 prevents thelight from the light-emitting diode 74 to spread, and allows to emitstraightforward, perpendicular to the base plate 65.

The second convex lens layer 79 and the third convex lens layer 79 alsoconverges the light allowing strong illumination of plants with thelights. Resultantly, employment of this light-emitting panel P as alighting device 3 enables further efficient plant cultivation.

The lamp 64 in FIG. 16 b is provided with a concave of about 0.9 mmdepth on the board 65, wherein the concave is mirror finished to reflectlights and the upper surface of the molding material 77 filled in theconcave is heaped up like convex lens.

Concerning inside of the concave 72, the bottom 86 is plane to mount theelectrode 75, while the side 87 is curved like concave mirror. The lightemitted from the light-emitting diode 74 is reflected by the inside faceand converged at some level and further converged by the convex lensfunction of the molding material 77.

The lamp 64 shown in FIG. 16 c is a combination of the three layerconvex lens structure shown in FIG. 16 a and the inside reflectingmirror structure shown in FIG. 16 b, thereby achieving both functions.The lamp 64 shown in FIG. 16 d has about the same structure as thatshown in FIG. 16 c. However it differs in the point that the depth ofthe concave is a little shallow, the electrode 75 is provided on thesurface of the board 65, and that the molding material 77 has wider areathan the concave so as to cover the electrode 75. This has substantiallythe same function as that shown in FIG. 16 c and further provides easybonding with the bonding wire 76.

The lamp 64 shown in FIG. 16 e is the same as the light-emitting elementshown in FIG. 16 b˜ 10 d except for the point that the upper surface ofthe molding material 77 is in plane with the surface of the board 65.Although this has no lens function, the light is converged at some levelby the concave mirror function of the concave 72 allowing a enough lightstrength to reach the plants.

FIG. 17 shows an embodiment of an electrical circuit to make a number oflight-emitting diodes. The Reference Numeral 1,2,3 . . . show positivepole wires and the Reference Alphabet a, b, c, d . . . show negativepole wires. The positive pole wires 1,2,3 . . . and negative pole wiresa, b, c intersect like a grid pattern to compose a matrix circuit 92 inwhich each cross way has a light-emitting element 1 a, 1 b, 1 c, 2 a, 2b, 2 c and so on. Based on a signal generated from a control which isnot shown in the figure, a voltage is applied to the positive polesselectively and the corresponding negative poles are grounded, whichmake the light being emitted from the light-emitting elements on thecross way of the working positive pole wires and the negative polewires. Arbitrary setting of the positive pole wire voltage enables toincrease or decrease illumination intensity of the light-emitting diodein a given location, which allows display of letters or specifiedpatterns.

When light-emitting elements in a particular area are degraded due tothe humidity and temperature causing decrease in illumination intensity,it is possible to increase illumination intensity of those elements tomake the whole intensity flat.

In this case, a feedback control circuit to obtain flat intensity on asteady basis is composed as follows; sensors using a photo transistorfor detecting the intensity in the specified area are provided inseveral locations, and an arithmetic circuit such as a central processor(micro processor) applies a suitable voltage to each positive pole wirebased on the output of those sensors, thereby nearly flat intensitybeing secured over the whole light-emitting panel. In the case of alight-emitting panel for use as plant cultivation, precise control suchas partial increase of the illumination intensity around the plants ornearby area can be performed.

In the case that such a precise illumination intensity control is notneeded, a publicly known series circuit 93 shown in FIG. 18A can beused. The Reference Numeral 94 in FIG. 18A is referred to a DC powersource, 95 to a fuse, and 14 a to a light-emitting element such as alight-emitting diode etc. Such a series circuit has a simple printpattern with short wiring. However, when conduction of a light-emittingdiode becomes broken away, whole span of the light-emitting panel or thelight-emitting unit goes out. Additionally, a parallel circuit 96 shownin FIG. 18B can be used in which broken away of a light-emitting element14 a does not have any effect on other light-emitting elements.Furthermore, as shown in FIG. 18C, a control wire 97 can be connected toevery light-emitting diodes arranged in matrix and the each wire ison-off controlled or illumination intensity controlled. In this casealso, micro-computers etc. can be used for performing precise control soas to make the illumination intensity flat or to change the illuminationintensity by each block.

The light-emitting panel P composed as described above is used not onlyfor plant cultivations but also for display panels 98 such as brakelights shown in FIG. 19 in single use or in combination use withmultiple panels. The Reference Numeral 99 is referred to the control.The display panel 98 is scarcely degraded in a high humidity environmentbecause of the lamp 64 being hermetically sealed.

Heat generated by the lamp 64 is efficiently radiated through the baseplate 60 preventing the heat accumulation in the panel, which enhancesdurability of the light-emitting element resulting in long and stableoperation of the display panel 98.

FIG. 20 shows the other embodiment of the light-emitting panel P. Inthis embodiment, the light-emitting panel P is located over the upperside of each shelf 102 of a stacked shelf 101. On the each shelf 102, acultivating vessel 103 for plants to be cultivated is arranged. By thisarrangement, the light from the lamp 64 is illuminated to the plants,and together with the supply of moisture and nutriment, temperaturecontrol, growth of the plants is promoted enabling efficient harvest.

In the case that the light-emitting panel is used as a lighting devicefor plant cultivation like above, the humidity is high in a room wherethe plant cultivating vessel 103 of the stacked shelf 101 is located.

However, since the lamp 64 is hermetically sealed between the base plate60 and the cover 62 and the inner side is very dried with the desiccant66, the lamp 64 is protected against the degradation due to humidity.Although, the amount of heat radiation from the lamp 64 is relativesmall compared with conventional fluorescent lamps, some amount of heatis radiated from the lamp 64 with its light-emission accumulating heatin the light-emitting panel P. But then, high heat conductivity of thebase plate 60 brings efficient heat radiation from the upper side of thelight-emitting panel P, protecting the lamp 64 also against thedegradation due to heat.

The light-emitting panel P in FIG. 21, the frame 61 made of syntheticresin is used in lieu of the frame accommodating a desiccant, whichlowers the heat conduction from the cover 62 to base plate 60.

Furthermore, in the light-emitting panel P, the piping 56 for passingthrough cooling medium such as cooling water is closely in contact withthe upper surface of the base plate 60. Cooling medium such asalternatives for chlorofluorocarbon or alcohol can be used, and coolingair can otherwise be passed through the piping or the duct. As well, inthe light-emitting panel P of FIG. 10 and in the light-emitting panel Pof FIG. 21, the board 65 is preferable to be closely in contact with thebase plate 60, which conducts generated heat in the lamp 64 from theboard 65 to the base plate 60 for efficient radiation.

Forced cooling of the base plate 60 by providing; good heat conductionfrom the board 65 to the base plate 60 enhancing heat radiation from thelamp 64; and the piping 56 for cooling medium, enables the more securetemperature control of the lamp 64. It is preferable for thelight-emitting elements such as light-emitting diodes to be in atemperature as low as possible in order to achieve high efficiency.

In addition, when the shelf 102 in FIG. 20 is composed of a pipe, it ispossible to run the cooling medium through the pipe into the piping 56.

In the light-emitting panel P3 of FIG. 22, the lamp 64 is directlymounted on the base plate 60, in which the base plate 60 serves also asthe board 65. Further in this embodiment, the frame sandwiched betweenthe base plate 60 and the cover 62 is omitted and simply the sealingmaterial 63 sustains the space in between.

This omission of the board(or the base) or the frame can be applied notonly to relatively small light-emitting panels but also to panels about1 m square by making the base plate 60 to serve as the board.

However, same as FIG. 11, the frame 61 can be provided. In addition, thelight-emitting elements described herein include semi-conductor LASERand other illuminant various semiconductor devices as well aslight-emitting diodes.

All the light emitting panel P employ the cover 62 made from a glassplate, but a cover made from a translucent synthetic resin plate such asan acrylic plate, and a laminated panel made from glass and syntheticresin plate or synthetic resin film can be employed.

1. A lighting-emitting panel, comprising; base plate; circuit boardmounted on the base plate; light-emitting unit provided with a number oflamps aligned and fixed on the circuit pattern of the circuit board;translucent cover placed with a space adjacent to the base plate;sealing material sandwiched between the base plate and the cover to keepthe space airtight; the lamps being fixed on the circuit board using aconductive adhesive; and a frame sandwiched between the base plate andthe cover, wherein a sealing material is packed around the frame, thespace is filled with inactive dry gas, and a desiccant and/or deoxidizeris accommodated inside of the frame.
 2. A lighting-emitting panelaccording to claim 1, further comprising; lamp provided with a concavereflecting plate; light-emitting element mounted on the reflectingplate; bonding wire to connect the light-emitting element and anelectrode; and translucent molding material of synthetic resin toenclose the light-emitting element and the reflecting plate.
 3. A lightemitting panel according to claim 1, wherein the conductive adhesive iscomposed of soldering cream.
 4. A light-emitting panel according toclaim 1, wherein the base plate serves as a circuit board.
 5. Alight-emitting panel according to claim 1, further comprising: a pipingfor cooling the light-emitting unit provided at a rear side.